1. Field of the Invention
The present invention relates to an image forming apparatus including an image bearer, on which a toner image is formed, and a lubricant supplying device that supplies lubricant to the surface of the image bearer. The present invention also relates to a process cartridge, which is detachably attached to a body of the image forming apparatus while mounting an image bearer, on which a toner image is formed, and a lubricant supplying device that supplies lubricant to the surface of the image bearer.
2. Discussion of the Background Art
The above-mentioned image forming apparatus such as an electronic copier, a printer, a facsimile, a complex machine combining these, etc., has been well known as discussed in Japanese Patent Application Laid Open No. 2002-91232. The image bearer includes a photoconductive member or an intermediate transfer member that receives transfer of a toner image formed on the photoconductive member. When the lubricant is coated on the surface of the image bearer, a friction coefficient of the surface is decreased and a friction caused between the surface of the image bearer and a member contacting the image bearer can be decreased. Thus, the friction on the image bearer surface can be suppressed, thereby a life of the image bearer can be prolonged.
As a lubricant, fatty acid metallic salt, such as zinc stearate, etc., is conventionally widely used. However, a characteristic of the lubricant apparently changes under the influence of discharge in the vicinity of the image bearer, thereby lubricity is relatively quickly loosed. For example, when a photoconductive member is employed as an image bearer, discharge is created between a discharge apparatus and the photoconductive member so as to charge the photoconductive member with a prescribed polarity. However, since the lubricant coated on the surface of the photoconductive member deteriorates due to the discharge. When an intermediate transfer member is employed as an image bearer, discharge is also created between a transfer apparatus and the intermediate transfer member so as to transfer a toner image formed on the intermediate transfer member to a transfer medium. However, since the lubricant coated on the intermediate transfer member surface also deteriorates due to the discharge.